This invention relates to an improved heat exchanger tube cleaning element capturing device.
It is known from the above-identified patents to connect individual elongated cleaning element capturing cages or baskets to both ends of longitudinally extending tubes disposed in a heat exchanger housing. The tube ends are held in position at both ends by transverse tube sheets. The baskets are adapted to contain shuttleable cleaning elements such as brushes. Fluid flowing in one direction through the tubes keeps the cleaning elements captured within their respective basket chambers, while the fluid discharges outwardly through openings in the basket walls. Upon reversal of fluid flow, the cleaning elements are forced out of their baskets and through the tubes to the baskets at the opposite tube ends to thereby perform a tube cleaning action.
Many baskets are designed of plastic and with their elongated body portions formed by alternating ribs and fluid flow-through slots which terminate in an annular outer end ring. The inner edge portion of the ring is alternately joined to the ribs or exposed to form the outer slot ends. For purposes of retaining a cleaning element within the basket and yet allowing the cleaning element to be removed outwardly for more complete access to the tube interiors, various retainer devices have been previously utilized. U.S. Pat. No. 4,124,065 illustrates a concept wherein various types of retainers can be removably attached to the outer end of the basket. One disadvantage of the removable retainer is that, being a separate piece, it can easily get lost prior to assembly to the basket. Furthermore, under certain conditions, it may accidentally release from an installed basket. U.S. Pat. No. 3,973,592 illustrates another less costly concept wherein a plurality of nib-like projections are formed integrally with the basket body and extend into the basket chamber to hold the cleaning element in place. Such projections, being fixedly positioned, may create difficulties in insertion and removal of the cleaning element therethrough and obstruct the basket interior.
It is a task of the present invention to create an improvement in cleaning element retaining, wherein the advantages of fully exposing the open basket end are maintained, for easy access, as with a removable retainer, while the above mentioned disadvantages of the latter are essentially eliminated. It is a further task to simultaneously provide the advantages of the less costly integral retainer without the aforementioned disadvantages of projections through which the cleaning element must pass and basket interior obstruction.
In accordance with the various aspects of the invention, a tube cleaning element capturing cage or basket is molded from a suitable slightly flexible plastic. The generally uninterrupted basket chamber terminates in an outer end portion defined by the basket body to which is integrally mounted a cleaning element retainer in the form of a closure. The closure is pivotally mounted to one side of the end of the basket body by a living hinge which permits swinging of the closure between a fully open position wherein the open-ended basket chamber is unobstructed for cleaning element installation and removal, and a fully closed position which retains the cleaning element within the basket during outward fluid flow. The closure is held in closed position by an integral latch on the side of the basket diametrically opposite the living hinge.